Gemological dichroscope

R. Winkel, Göttingen
Dichroscope, nickel plated brass with calcite (Iceland spar), focusable ocular in plush and silk lined leather case (17.3 x 11.1 x 5.2 cm). Tube (length 6.6 cm, diameter 2.1 cm) with wooden holder (lacquered black) and adjustable specimen holder on the front.
Signed "WINKEL | GÖTTINGEN" and serial number "7434". Also signed on the case "R. WINKEL | GÖTTINGEN", first half 20th century.

private collection